One of the most common tools found in toolboxes of contractors and do-it-yourselfers is the tape measure. It is used in all stages of a project from the beginning planning stages, through detailed design, construction and final inspection. It provides extremely accurate measurements at a minimal cost. However, while a tape measure works great with rigid materials and fixed distances, it does not do so well with non-rigid materials such as rope, wire, cable, tubing and the like. Typically, the user must lay the material down and lay the tape measure along side it. This can be a source of inaccuracy. Also, on many jobsites, there is not enough room to lay such material out. All of these difficulties can lead to costly mistakes if material is cut to a wrong dimension.
Several attempts have been made in the past to develop a device for accurately measuring the length of rope, cord, chain, or other elongate device with a portable device. U.S. Pat. No. 6,129,796, in the name of Steinberg et al., discloses an apparatus and method for dispensing and labeling cord, wherein the apparatus has at leas tone spool of cord where one can measure a length of cord, and a label is applied to the cord. The Steinberg et al. apparatus is not an electronic counting apparatus that displays the amount of cord played out as in the present invention.
U.S. Pat. No. 5,430,665, in the name of Jin et al., teaches a length measuring apparatus for accurately measuring the length of communication cable in a moving state, combining a marking and encoding system, and a detection system. The Jin et al. device, unfortunately, is not designed for portability and cannot be held by hand. Additionally, the Jin et al. device marks the object during the length measuring process.
U.S. Pat. No. 5,065,527, in the name of Shaw, describes a length measuring and positive drive apparatus including two rotatable members that surround the product with an encoder, display device, and means to cut or mark pre-set lengths. The Shaw device is not easily portable and is not designed to be conveniently and comfortably held by hand. Also, the Shaw device does not also incorporate an optical sensing mechanism.
U.S. Pat. No. 5,245,760, in the name of Smart et al., discloses an apparatus for the lineal measurement of continuous or stranded materials, such as cloth, comprising a gravity-operated contact wheel which generated incremental distance pulses when rotated, an electric eye, a support base, and a display means. In addition to the aforementioned prior art, the Smart et al. design is not suitable for hand-held portability and also does not include an optical sensing mechanism.
U.S. Pat. No. 4,798,003, in the name of Haglöf, teaches a thread meter comprising a holder for a thread reel, a counter with a rotary measuring wheel, and guides for the thread. In addition to the aforementioned prior art, the Haglöf design is not suitable for hand-held portability and also does not include an optical sensing mechanism.
U.S. Pat. No. 4,570,348, in the name of Amsler et al., describes an apparatus for measuring length of elongate cable, with a pair of rotating rollers, a magnetically-activated switch, a pulse-transmitting device, and a receiver for counting and displaying the number of pulses. The Amsler et al. device does not have a logic function to calculate the measured length of elongate material that passes therethrough. The Amsler et al. apparatus also utilizes a magnetically-activated switch and does not comprise an optical sensing mechanism and therefore does not fall under the scope of the present invention.
U.S. Pat. No. 4,400,882, in the name of Thornton, discloses a system for marking cables employing optical devices for measuring the distance impressions.
None of the prior art particularly describes a portable device that utilizes mechanical and optical readers to accurately measure the length of an elongate substrate, such as rope, cord, chain, etc. Accordingly, there exists a need for a means by which measurement of non-rigid material can be accurately made without the disadvantages as described above.